ia64/linux-2.6.18-xen.hg

view fs/affs/namei.c @ 524:7f8b544237bf

netfront: Allow netfront in domain 0.

This is useful if your physical network device is in a utility domain.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
author Keir Fraser <keir.fraser@citrix.com>
date Tue Apr 15 15:18:58 2008 +0100 (2008-04-15)
parents 831230e53067
children
line source
1 /*
2 * linux/fs/affs/namei.c
3 *
4 * (c) 1996 Hans-Joachim Widmaier - Rewritten
5 *
6 * (C) 1993 Ray Burr - Modified for Amiga FFS filesystem.
7 *
8 * (C) 1991 Linus Torvalds - minix filesystem
9 */
11 #include "affs.h"
13 typedef int (*toupper_t)(int);
15 static int affs_toupper(int ch);
16 static int affs_hash_dentry(struct dentry *, struct qstr *);
17 static int affs_compare_dentry(struct dentry *, struct qstr *, struct qstr *);
18 static int affs_intl_toupper(int ch);
19 static int affs_intl_hash_dentry(struct dentry *, struct qstr *);
20 static int affs_intl_compare_dentry(struct dentry *, struct qstr *, struct qstr *);
22 struct dentry_operations affs_dentry_operations = {
23 .d_hash = affs_hash_dentry,
24 .d_compare = affs_compare_dentry,
25 };
27 static struct dentry_operations affs_intl_dentry_operations = {
28 .d_hash = affs_intl_hash_dentry,
29 .d_compare = affs_intl_compare_dentry,
30 };
33 /* Simple toupper() for DOS\1 */
35 static int
36 affs_toupper(int ch)
37 {
38 return ch >= 'a' && ch <= 'z' ? ch -= ('a' - 'A') : ch;
39 }
41 /* International toupper() for DOS\3 ("international") */
43 static int
44 affs_intl_toupper(int ch)
45 {
46 return (ch >= 'a' && ch <= 'z') || (ch >= 0xE0
47 && ch <= 0xFE && ch != 0xF7) ?
48 ch - ('a' - 'A') : ch;
49 }
51 static inline toupper_t
52 affs_get_toupper(struct super_block *sb)
53 {
54 return AFFS_SB(sb)->s_flags & SF_INTL ? affs_intl_toupper : affs_toupper;
55 }
57 /*
58 * Note: the dentry argument is the parent dentry.
59 */
60 static inline int
61 __affs_hash_dentry(struct dentry *dentry, struct qstr *qstr, toupper_t toupper)
62 {
63 const u8 *name = qstr->name;
64 unsigned long hash;
65 int i;
67 i = affs_check_name(qstr->name,qstr->len);
68 if (i)
69 return i;
71 hash = init_name_hash();
72 i = min(qstr->len, 30u);
73 for (; i > 0; name++, i--)
74 hash = partial_name_hash(toupper(*name), hash);
75 qstr->hash = end_name_hash(hash);
77 return 0;
78 }
80 static int
81 affs_hash_dentry(struct dentry *dentry, struct qstr *qstr)
82 {
83 return __affs_hash_dentry(dentry, qstr, affs_toupper);
84 }
85 static int
86 affs_intl_hash_dentry(struct dentry *dentry, struct qstr *qstr)
87 {
88 return __affs_hash_dentry(dentry, qstr, affs_intl_toupper);
89 }
91 static inline int
92 __affs_compare_dentry(struct dentry *dentry, struct qstr *a, struct qstr *b, toupper_t toupper)
93 {
94 const u8 *aname = a->name;
95 const u8 *bname = b->name;
96 int len;
98 /* 'a' is the qstr of an already existing dentry, so the name
99 * must be valid. 'b' must be validated first.
100 */
102 if (affs_check_name(b->name,b->len))
103 return 1;
105 /* If the names are longer than the allowed 30 chars,
106 * the excess is ignored, so their length may differ.
107 */
108 len = a->len;
109 if (len >= 30) {
110 if (b->len < 30)
111 return 1;
112 len = 30;
113 } else if (len != b->len)
114 return 1;
116 for (; len > 0; len--)
117 if (toupper(*aname++) != toupper(*bname++))
118 return 1;
120 return 0;
121 }
123 static int
124 affs_compare_dentry(struct dentry *dentry, struct qstr *a, struct qstr *b)
125 {
126 return __affs_compare_dentry(dentry, a, b, affs_toupper);
127 }
128 static int
129 affs_intl_compare_dentry(struct dentry *dentry, struct qstr *a, struct qstr *b)
130 {
131 return __affs_compare_dentry(dentry, a, b, affs_intl_toupper);
132 }
134 /*
135 * NOTE! unlike strncmp, affs_match returns 1 for success, 0 for failure.
136 */
138 static inline int
139 affs_match(struct dentry *dentry, const u8 *name2, toupper_t toupper)
140 {
141 const u8 *name = dentry->d_name.name;
142 int len = dentry->d_name.len;
144 if (len >= 30) {
145 if (*name2 < 30)
146 return 0;
147 len = 30;
148 } else if (len != *name2)
149 return 0;
151 for (name2++; len > 0; len--)
152 if (toupper(*name++) != toupper(*name2++))
153 return 0;
154 return 1;
155 }
157 int
158 affs_hash_name(struct super_block *sb, const u8 *name, unsigned int len)
159 {
160 toupper_t toupper = affs_get_toupper(sb);
161 int hash;
163 hash = len = min(len, 30u);
164 for (; len > 0; len--)
165 hash = (hash * 13 + toupper(*name++)) & 0x7ff;
167 return hash % AFFS_SB(sb)->s_hashsize;
168 }
170 static struct buffer_head *
171 affs_find_entry(struct inode *dir, struct dentry *dentry)
172 {
173 struct super_block *sb = dir->i_sb;
174 struct buffer_head *bh;
175 toupper_t toupper = affs_get_toupper(sb);
176 u32 key;
178 pr_debug("AFFS: find_entry(\"%.*s\")\n", (int)dentry->d_name.len, dentry->d_name.name);
180 bh = affs_bread(sb, dir->i_ino);
181 if (!bh)
182 return ERR_PTR(-EIO);
184 key = be32_to_cpu(AFFS_HEAD(bh)->table[affs_hash_name(sb, dentry->d_name.name, dentry->d_name.len)]);
186 for (;;) {
187 affs_brelse(bh);
188 if (key == 0)
189 return NULL;
190 bh = affs_bread(sb, key);
191 if (!bh)
192 return ERR_PTR(-EIO);
193 if (affs_match(dentry, AFFS_TAIL(sb, bh)->name, toupper))
194 return bh;
195 key = be32_to_cpu(AFFS_TAIL(sb, bh)->hash_chain);
196 }
197 }
199 struct dentry *
200 affs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
201 {
202 struct super_block *sb = dir->i_sb;
203 struct buffer_head *bh;
204 struct inode *inode = NULL;
206 pr_debug("AFFS: lookup(\"%.*s\")\n",(int)dentry->d_name.len,dentry->d_name.name);
208 affs_lock_dir(dir);
209 bh = affs_find_entry(dir, dentry);
210 affs_unlock_dir(dir);
211 if (IS_ERR(bh)) {
212 return ERR_PTR(PTR_ERR(bh));
213 }
214 if (bh) {
215 u32 ino = bh->b_blocknr;
217 /* store the real header ino in d_fsdata for faster lookups */
218 dentry->d_fsdata = (void *)(long)ino;
219 switch (be32_to_cpu(AFFS_TAIL(sb, bh)->stype)) {
220 //link to dirs disabled
221 //case ST_LINKDIR:
222 case ST_LINKFILE:
223 ino = be32_to_cpu(AFFS_TAIL(sb, bh)->original);
224 }
225 affs_brelse(bh);
226 inode = iget(sb, ino);
227 if (!inode) {
228 return ERR_PTR(-EACCES);
229 }
230 }
231 dentry->d_op = AFFS_SB(sb)->s_flags & SF_INTL ? &affs_intl_dentry_operations : &affs_dentry_operations;
232 d_add(dentry, inode);
233 return NULL;
234 }
236 int
237 affs_unlink(struct inode *dir, struct dentry *dentry)
238 {
239 pr_debug("AFFS: unlink(dir=%d, \"%.*s\")\n", (u32)dir->i_ino,
240 (int)dentry->d_name.len, dentry->d_name.name);
242 return affs_remove_header(dentry);
243 }
245 int
246 affs_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd)
247 {
248 struct super_block *sb = dir->i_sb;
249 struct inode *inode;
250 int error;
252 pr_debug("AFFS: create(%lu,\"%.*s\",0%o)\n",dir->i_ino,(int)dentry->d_name.len,
253 dentry->d_name.name,mode);
255 inode = affs_new_inode(dir);
256 if (!inode)
257 return -ENOSPC;
259 inode->i_mode = mode;
260 mode_to_prot(inode);
261 mark_inode_dirty(inode);
263 inode->i_op = &affs_file_inode_operations;
264 inode->i_fop = &affs_file_operations;
265 inode->i_mapping->a_ops = (AFFS_SB(sb)->s_flags & SF_OFS) ? &affs_aops_ofs : &affs_aops;
266 error = affs_add_entry(dir, inode, dentry, ST_FILE);
267 if (error) {
268 inode->i_nlink = 0;
269 iput(inode);
270 return error;
271 }
272 return 0;
273 }
275 int
276 affs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
277 {
278 struct inode *inode;
279 int error;
281 pr_debug("AFFS: mkdir(%lu,\"%.*s\",0%o)\n",dir->i_ino,
282 (int)dentry->d_name.len,dentry->d_name.name,mode);
284 inode = affs_new_inode(dir);
285 if (!inode)
286 return -ENOSPC;
288 inode->i_mode = S_IFDIR | mode;
289 mode_to_prot(inode);
291 inode->i_op = &affs_dir_inode_operations;
292 inode->i_fop = &affs_dir_operations;
294 error = affs_add_entry(dir, inode, dentry, ST_USERDIR);
295 if (error) {
296 inode->i_nlink = 0;
297 mark_inode_dirty(inode);
298 iput(inode);
299 return error;
300 }
301 return 0;
302 }
304 int
305 affs_rmdir(struct inode *dir, struct dentry *dentry)
306 {
307 pr_debug("AFFS: rmdir(dir=%u, \"%.*s\")\n", (u32)dir->i_ino,
308 (int)dentry->d_name.len, dentry->d_name.name);
310 return affs_remove_header(dentry);
311 }
313 int
314 affs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
315 {
316 struct super_block *sb = dir->i_sb;
317 struct buffer_head *bh;
318 struct inode *inode;
319 char *p;
320 int i, maxlen, error;
321 char c, lc;
323 pr_debug("AFFS: symlink(%lu,\"%.*s\" -> \"%s\")\n",dir->i_ino,
324 (int)dentry->d_name.len,dentry->d_name.name,symname);
326 maxlen = AFFS_SB(sb)->s_hashsize * sizeof(u32) - 1;
327 inode = affs_new_inode(dir);
328 if (!inode)
329 return -ENOSPC;
331 inode->i_op = &affs_symlink_inode_operations;
332 inode->i_data.a_ops = &affs_symlink_aops;
333 inode->i_mode = S_IFLNK | 0777;
334 mode_to_prot(inode);
336 error = -EIO;
337 bh = affs_bread(sb, inode->i_ino);
338 if (!bh)
339 goto err;
340 i = 0;
341 p = (char *)AFFS_HEAD(bh)->table;
342 lc = '/';
343 if (*symname == '/') {
344 while (*symname == '/')
345 symname++;
346 while (AFFS_SB(sb)->s_volume[i]) /* Cannot overflow */
347 *p++ = AFFS_SB(sb)->s_volume[i++];
348 }
349 while (i < maxlen && (c = *symname++)) {
350 if (c == '.' && lc == '/' && *symname == '.' && symname[1] == '/') {
351 *p++ = '/';
352 i++;
353 symname += 2;
354 lc = '/';
355 } else if (c == '.' && lc == '/' && *symname == '/') {
356 symname++;
357 lc = '/';
358 } else {
359 *p++ = c;
360 lc = c;
361 i++;
362 }
363 if (lc == '/')
364 while (*symname == '/')
365 symname++;
366 }
367 *p = 0;
368 mark_buffer_dirty_inode(bh, inode);
369 affs_brelse(bh);
370 mark_inode_dirty(inode);
372 error = affs_add_entry(dir, inode, dentry, ST_SOFTLINK);
373 if (error)
374 goto err;
376 return 0;
378 err:
379 inode->i_nlink = 0;
380 mark_inode_dirty(inode);
381 iput(inode);
382 return error;
383 }
385 int
386 affs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
387 {
388 struct inode *inode = old_dentry->d_inode;
390 pr_debug("AFFS: link(%u, %u, \"%.*s\")\n", (u32)inode->i_ino, (u32)dir->i_ino,
391 (int)dentry->d_name.len,dentry->d_name.name);
393 return affs_add_entry(dir, inode, dentry, ST_LINKFILE);
394 }
396 int
397 affs_rename(struct inode *old_dir, struct dentry *old_dentry,
398 struct inode *new_dir, struct dentry *new_dentry)
399 {
400 struct super_block *sb = old_dir->i_sb;
401 struct buffer_head *bh = NULL;
402 int retval;
404 pr_debug("AFFS: rename(old=%u,\"%*s\" to new=%u,\"%*s\")\n",
405 (u32)old_dir->i_ino, (int)old_dentry->d_name.len, old_dentry->d_name.name,
406 (u32)new_dir->i_ino, (int)new_dentry->d_name.len, new_dentry->d_name.name);
408 retval = affs_check_name(new_dentry->d_name.name,new_dentry->d_name.len);
409 if (retval)
410 return retval;
412 /* Unlink destination if it already exists */
413 if (new_dentry->d_inode) {
414 retval = affs_remove_header(new_dentry);
415 if (retval)
416 return retval;
417 }
419 bh = affs_bread(sb, old_dentry->d_inode->i_ino);
420 if (!bh)
421 return -EIO;
423 /* Remove header from its parent directory. */
424 affs_lock_dir(old_dir);
425 retval = affs_remove_hash(old_dir, bh);
426 affs_unlock_dir(old_dir);
427 if (retval)
428 goto done;
430 /* And insert it into the new directory with the new name. */
431 affs_copy_name(AFFS_TAIL(sb, bh)->name, new_dentry);
432 affs_fix_checksum(sb, bh);
433 affs_lock_dir(new_dir);
434 retval = affs_insert_hash(new_dir, bh);
435 affs_unlock_dir(new_dir);
436 /* TODO: move it back to old_dir, if error? */
438 done:
439 mark_buffer_dirty_inode(bh, retval ? old_dir : new_dir);
440 affs_brelse(bh);
441 return retval;
442 }